ESP32 Forum

Posted: **Sat Feb 03, 2024 1:46 pm**

Hi
I have a program that issues at midnight the summary of the past day.
It should issue the summary in a line appended to a file. That file should be in the csv format, for post processing in Excel.
All is done now.

But I would like to begin the line with a date identifier. Only day/month. And that identifier should be the day of yesterday (because I print after midnight)
Has someone got an idea how to code that in c++?

Thank you for any hint...

Posted: **Sat Feb 03, 2024 9:39 pm**

Finally I found out alone.

Code: Untitled.cpp Select all


//***Variables for Time***

tm* timeinfo;  

tm* yesterdaytimeinfo;  

time_t now;

time_t yesterdaynow;

static char charbuff[120];  //Char buffer for many functions





//*** In program ***

yesterdaynow = now - 86400;

yesterdaytimeinfo = localtime(&yesterdaynow);

strftime(charbuff, 30, "%x ", yesterdaytimeinfo);

println();

print(charbuff);

Enjoy!

ESP32 Forum

How to print the date of yesterday?

How to print the date of yesterday?

Re: How to print the date of yesterday?